<!DOCTYPE html>
<html>
<head>
    <title>Liquid Helium Container Diagram</title>
    <style>
        body {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            background-color: #f0f0f0;
        }
        canvas {
            border: 1px solid #ccc;
            background-color: #ffffff;
        }
    </style>
</head>
<body>
    <canvas id="physicsCanvas" width="500" height="400"></canvas>
    <script>
        const canvas = document.getElementById('physicsCanvas');
        const ctx = canvas.getContext('2d');

        // Style settings
        ctx.strokeStyle = 'black';
        ctx.lineWidth = 3;
        ctx.fillStyle = 'black';
        ctx.font = '22px sans-serif';
        ctx.lineJoin = 'round'; // To mimic slightly rounded corners of a hand-drawn image

        // --- Draw the containers ---
        
        // Use separate paths for each container to avoid unintended connections
        
        // Inner Container (for liquid helium)
        ctx.beginPath();
        // U-shaped body
        ctx.moveTo(190, 150);
        ctx.lineTo(190, 260);
        ctx.lineTo(310, 260);
        ctx.lineTo(310, 150);
        // Neck lines
        ctx.moveTo(230, 80);
        ctx.lineTo(230, 150);
        ctx.moveTo(270, 80);
        ctx.lineTo(270, 150);
        ctx.stroke();

        // Outer Container / Jacket
        ctx.beginPath();
        // U-shaped body
        ctx.moveTo(170, 140);
        ctx.lineTo(170, 280);
        ctx.lineTo(330, 280);
        ctx.lineTo(330, 140);
        // Neck lines
        ctx.moveTo(220, 80);
        ctx.lineTo(220, 140);
        ctx.moveTo(280, 80);
        ctx.lineTo(280, 140);
        ctx.stroke();

        // --- Draw the labels ---
        
        // "liquid helium"
        ctx.textAlign = 'center';
        ctx.textBaseline = 'middle';
        ctx.fillText("liquid", 250, 200);
        ctx.fillText("helium", 250, 225);

        // "liquid nitrogen"
        ctx.textAlign = 'left';
        ctx.fillText("liquid", 340, 205);
        ctx.fillText("nitrogen", 340, 230);

        // "atmospheric pressure"
        ctx.textBaseline = 'top';
        ctx.fillText("atmospheric", 290, 95);
        ctx.fillText("pressure", 290, 120);

        // "Fig. 2.38."
        ctx.textAlign = 'center';
        ctx.font = '20px sans-serif';
        ctx.fillText("Fig. 2.38.", 250, 330);

    </script>
</body>
</html>